Cigarette smoking reduces sperm count and motility and increases the number of abnormal sperm. Smoking also adversely affects hormone levels and may affect the cells in the testes that produce testosterone. Like cigarette smoking, use of marijuana also can adversely affect sperm count, sperm motility, and sperm morphology. It can also reduce plasma testosterone levels. Anabolic steroids influence production of reproductive hormones and can reduce fertility. Use of cocaine also negatively affects sperm parameters as well as the ability of sperm to penetrate cervical mucus. Opiates (heroin, morphine) may reduce fertility in men by altering hormone production.

Numerous chemicals used in industry or found in the environment as contaminants have been linked to male infertility. These include organochlorine pesticides, dioxins (used to bleach paper products), and vinclozolin (a fungicide used on food). These chemicals are thought to reduce fertility by disrupting hormone function. Avoid exposure to these chemicals whenever possible.

Unprotected sexual intercourse (intercourse without a condom) increases your risk of developing a sexually transmitted disease (STD). Several STDs, including
gonorrhea
and
chlamydia
, often produce no symptoms, especially in men, so you may not know you are infected. Untreated STDs can cause scarring in the sperm-carrying tubes, which reduces the number of sperm in semen and increases the risk of fertility problems. The more sexual partners you have, the greater your chance of contracting an STD. Using condoms and minimizing the number of sexual partners you have will reduce your risk of getting an STD.

There are many medications which could cause either subfertility or infertility. These include the following categories:

High body fat can alter hormone metabolism. If you are overweight, consult with your doctor or a registered dietitian to find out what weight is healthy for you and to get help in attaining it.

Moderate exercise increases sperm production and may have beneficial effects on fertility. However, excessive exercise, such as that performed by long-distance runners, reduces sperm production.

The testicles are easily damaged during vigorous sporting events or fights. These injuries can cause inflammation that reduces the blood supply to the testicles, which can permanently damage sperm-producing cells.

Underwear and clothing that is tight and constricting may reduce blood flow in the groin and adversely affect sperm production.

Certain bicycle seats may cause circulatory and neurologic damage in the groin that can affect erectile function.

Revision Information

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.